Tooth Cavities: Symptoms, Causes & Treatments

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Tooth cavities are the result of tooth decay and a common dental problem. Thankfully, detecting decay at its earliest stages can save you some uncomfortable toothaches (not to mention those dental bills!). By limiting your intake of sugary foods and brushing twice a day with fluoride toothpaste, you should be able to avoid tooth cavities altogether.

What Is a Tooth Cavity?

Also known as dental caries, tooth cavities are the holes in teeth caused by tooth decay. They start with the plaque bacteria naturally found on your teeth, and when you eat sugary foods, these bacteria break some of the sugars down into acids. Thankfully, fluoride toothpaste can help protect your teeth against this, but eating too many sugary foods can produce enough acid to slowly eat away at the tough enamel surrounding your teeth ­– eventually causing the tooth surface to collapse, creating a tooth cavity. Read on to discover the causes of cavities and learn how to spot the signs of tooth decay early.

Tooth Cavity Symptoms

Tooth enamel has no nerves, which makes it easy for decay to start without you even realising. Treating tooth decay early can help stop further damage before a cavity forms and save you unnecessary discomfort. If you notice any of these signs, you should speak to your dentist immediately.

  • Toothaches are usually the first sign that you may have a tooth cavity. Mild pain might mean the cavity is relatively new and could be easily treated, while a severe toothache could point to a greater level of tooth decay.
  • Tooth sensitivity is another common cavity symptom. If your teeth are generally okay with hot, cold or sweet foods, an increase in sensitivity is something you should speak to your dentist about.
  • Heavy staining on your teeth could also be a sign of cavities. If you notice brown, black, or even white staining on your teeth, speak to your dentist to ensure it isn’t linked to tooth decay.

An unpleasant taste in your mouth and bad breath can be caused by cavities and tooth decay as bad-tasting and foul-smelling bacteria grows inside the toothiv.

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What Causes Tooth Cavities?

Tooth decay, and the resulting cavities, usually caused by plaque acids dissolving away the enamel surrounding your teeth over time. When you eat or drink sugary things in particular, the bacteria in plaque produce acid, which gradually breaks down the surface of your enamel, causing tooth decay. If a cavity develops, the bacteria can access the dentine underneath, which can cause sensitivity and paini.

How to Prevent Tooth Cavities

Although tooth cavities are a common problem, you can help avoid them in the first place by following two simple rules: a healthy diet and a consistent oral care routine.

  • Healthy eating is the key to healthy teeth. By cutting back on foods and drinks that are high in sugars or processed carbohydrates, you can help stop tooth decay before it starts – meaning you have less of a battle to fight against decay when you brush. Fortunately, our teeth can repair some of the damage done during the day while we sleep, so try to avoid eating anything sugary after your nightly brush.
  • Following a healthy diet is particularly important for children's oral health, whose milk teeth are more vulnerable than adult teeth. For more information on looking after your child’s teeth, visit our kids' oral care information page, where you’ll find everything you need to know to keep their pearly whites protected, and free of tooth cavities, throughout their development.

  • Brushing for at least two minutes, twice a day, with fluoride toothpaste is the key to giving your teeth the care they need. A thorough clean between each tooth (including the ones hiding at the back) can help flush out lingering plaque and prevent tooth cavities from forming. Use a great-tasting toothpaste like Aquafresh Triple Protection Fresh & Minty to leave you feeling clean and protected after each brush. And for children, try our specially formulated Little Teeth Toothpaste for kids ages 3 to 5 – don’t forget the Aquafresh Little Teeth Toothbrush, available with crocodile, bunny, shark and tiger bristle protect heads, to add some fun to your brushing routine.
  • Regular dentist check-ups are essential to help spot decay and treat it before it leads to tooth cavities. Professional teeth cleaning can also be helpful if you struggle with brushing or cleaning between your teeth, giving your mouth the best chance to stay strong, healthy and cavity-free.

Treatment for Tooth Decay and Cavities

While prevention is better than cure when it comes to our oral health, there are treatment options available to help repair tooth decay and cavities and leave your mouth pain-free and healthy once more. For early-stage tooth decay, your dentist may recommend limiting the amount of sugary food and drink you consume or applying a fluoride gel directly to the affected tooth to mend some of the damageii. If a tooth cavity has formed, you may need one of the following treatments:


A tooth cavity can’t be reversed, so you may need to have a filling. This is where your dentist will repair the tooth decay damage by filling the hole with a resistant material. This can stop the toothache, but the tooth will never be as strong as it once was: it's much better to avoid cavities in the first place rather than treat them if they appear.


If the tooth cavity has already become too big to fill, you may need a crown or dental cap fitted to protect the tooth. This involves removing the tooth decay and filling the hole or covering the tooth to stop further deteriorationiii.


In some extreme cases, the tooth may need to be removed altogether – making it all the more important to eat healthily, cultivate a consistent dental care routine and have regular check-ups to spot any signs of decay.

Tooth decay, while common, can cause tooth cavities when left untreated. You can avoid these painful and annoying issues by maintaining an excellent oral hygiene routine, being mindful of how many sugary foods and drinks you’re consuming and attending regular check-ups at your dentist. For more information on looking after your teeth, visit our information page.

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  1. Bupa. Tooth Decay. Accessed October 6th, 2021.
  2. NHS. Tooth Decay. Accessed October 6th, 2021.
  3. NHS. Tooth Decay. Accessed October 6th, 2021.
  4. Bahadır Uğur Aylıkcı and Hakan Çolak. Halitosis: From diagnosis to management. Accessed April 27th, 2022.